1. Field of the Invention
The present invention relates to a component of a catalyst for polymerizing an olefin, the catalyst for polymerizing an olefin, and a process for polymerizing an olefin.
2. Description of the Related Art
In olefin polymerization, there have been popularly used catalysts comprising a transition metal component and a co-catalyst component. In particular, catalysts wherein metallocene is used as the transition metal component have come into a wide use, because such catalysts provide a polymer showing excellent mechanical properties and thermal properties due to the excellent uniformity of the resultant polymer.
As a co-catalyst component for converting the metallocene to an activated cationic form for polymerizing an olefin, boron compounds such as B(PhF6)3, Ph3 CB(PhF5)4 and PhNMe2 HB(PhF5)4 are famous. However, these compounds are soluble in a solvent to be used for the olefin polymerization like the transition metal compounds, and involve the problem that they are not suited for particle-form-polymerization for producing a polymer as particles.
On the other hand, there have been made investigations on solid co-catalyst components adapted for the particle-form-polymerization and, as examples thereof, there are illustrated an example of using silica having been surface-treated with trimethylchlorosilane (Journal of Molecular Catalysis A: Chemical 130,121(1998)) and an example of using ion-exchangeable layered silicate (Japanese Patent Laid-Open No. 1660/1999). However, as far as the inventors have understood, these co-catalysts involve such problems as that they are insufficient in catalytic activity or ability of controlling molecular weight distribution of a resultant polymer, that they are seriously insufficient in controlling the form of resultant polymer particles, or that a considerable investment is required for an equipment for producing a carrier necessary therefor.
Further, it has recently been reported that novel complexes containing a central metal atom of iron, nickel, cobalt, palladium or the like as a single site catalyst in place of metallocene can be used in combination with a suitable activator for olefin polymerization (Angew. Chem. Int. Ed., 1999, p. 428, CURRENT SCIENCE 2000, p1325). Catalyst components having superior activating ability are also needed for such single site catalysts.